Spring die cushion



R. D. KING.-

S PRING DIE CUSHION.

APPLICATION FILED APR.15. I918.

1,351,91 1 PatentedSept. 7, 1920.

2 SHEETSSHEET 1.

R. 0. KING. SPRING DIE CUSHION.

- APPLICATION FILED AP Patented p 1920' 2 SHEETSSHEETZI E &

jivezvff RoY n. xiive, 1 or cnrcaeo,,irrlinois, Assieivonor m as ic mess-mos; or I onroneo, ILLINOIS 'sPRinG- I E onsmon.

1351, 911; ii i I To aid whom it m y concern Be itknown that I, ltor DJ 1mm; a citi- F zen oi the United'States, residing atUhicage, in thecountyfof 'Coolrand saw of lllmols, have invented certain 'new'fand use ful Improvements in [Spring-Die Gushions,

ofwhich the followingis aspecification. 'lllns invention relates 1n 1 geI'ler'al; to presses' of the type commerc'ially known {as V punch presses, andh'asmore particular-reference tomechanism ior-y'ieldingly sustainmg the draw-ring sothat the holding pres-' sure on the metalbemg drawn into form will be great enough to prevent wrinkling at the beginning of? the stroke, but at the" same timc will not be'so great as to cause the metal to tear near the end of the stroke;

The use of springs for yieldingly sustai'ning the draw-rings has been impractical and unsatisfactory prior to my invention for the reason that the resistance ojllered-bylthe springs would beincreased as the springs were compressed toward the I end of the op-i crating stroke, with the result that thepres sure or gripping actionon the metal-being formed would be increased to suchan extent that the metal would be torn near tlie end of the stroke, if the pressure at the begin ning of the stroke wassufli'cient toiprevent wrinkling, and on the otherhand, if'fthe springs were adjusted so that the pressure at the end of the stroke was SUlllCl'Gllt to hold the metal without causing it to. tear, the pressure at the beginning of the stroke would be insufficient to prevent wrinkling ef the yielding support for the ilrafw-ring' in which springsare employed for cushion'ingpur-j p p l and 2. 'Amovable m'ember -1S,,s1milar in poses, but t he1gradually increasing pressure of these springs is, modifiedbywtoggle :leve'r mechanism so that the resultantresistance offered to movement" ofthe. draw-rlng may be substantially constant during its entire stroke; furthermore my invention contemplates adjustabllity whereby this modified resistance to movement [of thedraw-ring may be increased or diminishedtoward the end of the operative stroke so as to afford a varying pressure by the draw ring when- E b s'pec ii aaon i Letters Patent? 7 Patented Sept. '7, 1920.; V ratification filed April :15, 1918. ser aiNoLme'stJa- 7 'sion may be regulatedand adjusted to suit. V

the requirements of any particular work,

which it maybe desirable to perform upon 4 the machine.

one preferredembodiment thereof on the accompanying I drawings reference to which, when-considered in connection with the following description, the structure, op

eration and many of the inherent advan- V readily un- For the purposeof facilitating an under standing of my invention, I have illustrated Figure 1 is Fig.2 is a vertical seetionalyview taken at right angles to the view shown in Fig. 1,--

and Fig. 3 is a horizontal sectional view on the line 33 of Fig. 2. I p

I 'On the drawings reference character 5 indicates the bolster plate of a punch press of well known construction upon which table is mounted to the base block 6, carrying the die or forming member 7. The drawring 8, surrounding the forming member, is limited in its upward movement by the flange of the cutting die 9, carried by the base block6, and this draw-ring isv supportedby a plurality of upright bolts or rods 11, extending throughsuitable openings in the base block and carried at'their lower ends upon the movable section 12 of 1 the table, which section is'inturn supportedv by a horizontallydisposed member 13.. r r I A pair of rods '14: and 15 are suspended from the, bed 5, and a stationary member 16 is supp'ortedpn these .rods by nuts 17 threaded onto thO I'OIlS, as: shown in- Figs.

structure to the member "16, is slidably disposed uponthe'rods intermediate their ends and upward movement of thismember is, limited by sleeves 19 and 21,,surround1ng the rods 1 land'15 between the member 18 and the'lower face of the bed 5. It will be observed that themembers 1 6 and'18 are provided with apertures-10, and 20 respectively spaced inwardly from the ends there-' of to receive the rods 14 and.15 should the structure of any particular press require :theserods to be located more. closely to gether. p i A rod 22 rigidly, connected atjits upper .lllg preferably provided 'to maintain the adjusting wheel in adjusted position; It will be manifest that downward movement of the member 13 caused by downward movement of the draw-ring 8 when a draw ing operation over the forming member 7 s being performed, will, through the rod 22 and adjusting wheel 23, cause a similar downward movement oi the member 18. to-

ward the stationary member 16. Resistance to this movement of the member 18 will be transmitted to the draw-ring 8 so as to pro duce the requisite pressure of the draw-ring upon, the metal being formed.

Thisresistance is afforded inthe instance by spring and togglelever mecha nism, which will now be described.

The stationary member 16 and the movable member 18 are each provided on their Opposed faces with bearing sockets, or de pressions, adapted to receive the correspondingly shaged ends oi a plurality of sets of toggle levers; four of these sets are shown in the drawings and indicated by reference characters 25, 26, 27 and 28, respee tively. The upper ends of the sets of levers 25 and 26 are engaged with the ineniljier 18, andthc lower ends of the sets 2? and 28 are engaged with the member 16. The opposite ends of the levers 25 and 27 are engaged in suitably formed sockets on the inner face of a horizontally movable pressure iember 29, while corresponding ends of the toggle levers 26and 2S similarly engage eorrespondingly shaped recesses in the inneriace of an opposed horizontally movable pressure member 31. These two members 29 and. 31 are mounted upon a plurality of bolts or rods 32 which extend laterally beyond the member 31, as shown in Figs. 2 and A plurality of expansion springs 33 and 34 are disposed upon each of said rods and. niai itainwl, under tension by being 7 compressed l. etween the outer Face of the member 31, and abutment washer 35 disposed upon theoiiter-end of the rod 32 and maintained in ad usted position by an adjusting nut 36. These springs may vary in number as conditions require; but for pur decrease the length of the springs and diminish the likelihood of buckling which has a tendency to occur when extremely long springs are used. 7

Since the resistance of an expansion present spring increases as its length is decreased under compression, it will be manifest that unless some compensating mechanism be employed, the increased resistance afforded by the springs would increase the pressure ber 18, the upper and lower ends of the toggle levers are moved relat vely toward each other and the central ends are correspondingly moved laterally, therebyforcing the pressure members 29 and 31 apart against the tension of the springs 33 and 34; and as the inner ends of the toggle levers move laterally, and their outer. ends vertically, the leverage of these members in creases, and this increase oii-sets the increase in resistance offered by the springs and 3%, with the result that the ultimate resistance offered to movement oi the drawring is substantially uniform throughout the length of its stroke.

The variation in the leverage of the toggle levers will obviously depend upon their initial or normal position; in other words upon the normal distance between the members 16 and 18.

By regulating the normal distance be tween these two members by adjustment of the adjusting wheel 23 the extent of variation of the leverage, and consequently the modification of the spring pressure as. applied ;to the draw-ring, may be modified. The wheel 23 will usually be so adjusted that the toggle levers will just compensate for the incl-casein tension of the expansion springs as they are compressed, so that the resultant resistance offered to movement of the draw-ring will be substantially constant throughout the length of its operative stroke. If preferred, however, the leverage may be regulated so that the pressure of the draw-ring will be less toward the end of its stroke than it is at the beginning, and if do sirable, the pressure can be regulated so that it would increase toward tlie end oi the stroke, but this latter condition would not often be desirable in the operation of presses of this character. The spring pressure, ofcourse, may be regulated by adjustment of the abutment washers 35.

In setting up a press or" this character, it is desirable that the press he turned over by hand and that the draw-ring be depressed without oilering any resistance in order that the longth'ofthe stroke may be determined. Bymypresent construction the pressure on the draw-ring maybe very easily relieved by threading the adjusting wheel 23 toward the top of the rod 22 thereby relieving-"any thrust upon the members '16 and. 18. So'far as I am aware, this ability to relieve the pressure on the draw-ring without .disassembl'ing the cushion or resistance device machine. I I V It is believed that the construction and 0ption, but it should be obvious that various changes in the sizes, shape, proportions and ar angement of the various parts llustrated and described may be resorted towithont, departing from the essenceof the nvention,

as defined in the following claims.

I claim:

1. In aspring die cushion, the. combina- 7 :oftl e lower elements with theinembers of" SillClPiLll, p 7. In a spring die 011Sl1l011,.l1l16 combina 'tion of a fixed member, a movable member,

a pair of opposed members movable sii'bstan .tially at right angles to said movable memtion of a member adaptedto be fixed to a stationary part of a pres s,-a member adapted to be attached to a movable part of said press, toggle levers interposed between said members, a spring arranged to resist move-" ment of said members, and means for ad usting the normalrelativepositionof said members' whereby thevariable resistanceoffered by said spring may be regulated. y 2. In a spring die cush1on,the comb1nation of amember adapted tobe fixed to a stationary part of a press, ameinber adapted to be attached to a movable part of said press, to gle levers interposed between said Y members, a spring arranged to resist movement of said members, means foradpisting the normal relative position of said members whereby the variable resistance. oflered by said spring may be regulated,-and means for adjustlng the tension of said SPI'lD 3. In a spring die cushion, the combina tion of a member adapted torbe fixed to a stationary part of a press, a member adapt ed to be attached to a movable part of said press, toggle levers disposed atan angle between said members, spring means for 01)- posing movement of said'levers and means whereby the normal angularity of said 1e-- vers may be adjusted.

4;. In spring die cushion,- the combina-" tion. of a membe' adapted to be fixed to a stationary part of a press, a member adapted to be attached to a movable part of said 7 press, toggle levers disposed at an angle between said members, means whereby the normal angnlarity ofsaid levers may be adjiisted, a spring arranged to offer resistance to movement of said toggle levers, and

means l er adjusting the tension of said spring.

5. In a spring die cushion, the combina tien of a fixed member, a movable member, toggle levers disposed at an angle between said members, a spring arranged to resist movement of said toggle levers, means whereby the tension of said spring may be adjusted, and means foradjusting thenor mal relative position of said members to vary the. .norinalangnlarityi of said toggle levers whereby to regulate the variation in the re- -ES1StQI1CBfOlfelBd bysaidspring to the relative movement of said toggle levers and 7 members" l 7 .6. In a spring die ciishion,"the combina tion of: a pair of relatively movable members, afsecond pair Oi relatively movable four lever elements, theii 'iper and lower elements of each set being arranged in crossed relation so that the upper elementsv oil? eachset engage with the members'of said second pair below the points of engagement,

ber, each of the aforesaid members being provided 'WlthfSOCkGtS, toggle levers disposed in crossed relation between the members and seated at'their ends in said sockets,

and a spring acting on said pair of members in opposition to separating movement of said members under the action of said toggle levers.

In a springdie cushion the combination of a fixed member, a vertically movable member, a pair of horizontally movable -members, all of said members being pronvided with sockets, a plurality of toggle levers seated in the sockets of said members so as to be disposed in crossedrelation between the members, the lower levers being engaged with said horizontally movable members above the centers of'said members and the upper toggle levers being engaged with said horizontally movable members below the centers of said members, a spring arranged to oppose sepa 'ating movement of said horizontally movable. members, means. for ad uStmg'the tension of said spring, and means for adpisting the normal relative positions ofsaid members and toggle levers.

9. In a device of-the character described, the combination of a stationary member, a movable member, means for regulating the normal distance between said members, toggle lever mechanism operatively connected with said stationary and movable members, and means for yieldingly'resisting movementof said toggle lever mechanism, said toggle lever mechanism being adapted to transform the variable resistance of said yieldii'igly resisting means into a substan. tially invariable resistance opposed to move- 'DIGllt of said movable member.

10. Ina device of the character described,

the combination of a movable member,

of said member. may be caused to decrease toward the end of the operative stroke of said member.

11, In a deviccoit the character described, the combination of a movable member, means for yicldingly resisting movement of said member, andadjustable means whereby the resistance to movement of said member may be caused to vary during the stroke oi? said member.

12, in a device of th character described, the combination of a movable member, means for yieldingly resisting movement of said member, and means whereby the resistance offered to movement of said member may be caused to increase or diminish at will as said member approaches the end of its operative stroke 13. In a device of the character described, the combination of a movable member, spring and toggle mechanism for yieldingly resisting movement of said member, means for varying the, normal tension of said spring, and means for regulating" the normal position of said toggle mechanism so that the resistance of said spring to movement of said member may be modified at will.

14. In a spring die cnshiomthe combination of a pair of relatively movable members, a second pair of members movable substantially at right angles to said first pair, each member of each pair being provided with sockets, toggle levers disposed between said members, said levers being arranged in crossed relation between thesecond. pair of members so that thethrnst of said levers upon the members of said pair is exerted away from the medial line of said members, and a spring arranged to yicldingly oppose separating movement of said second pair of members. v 7 15. In a spring die cushion, the combination et a pair ref-relatively movable membcrs, a second pair of relatively movable members arranged at substantially right angles to said first pair, toggle levers disposed between said pairs or members and a. spring arranged to oppose separating movement of said second pair of members under the action of said toggle levers, the upper and lower members of saidtoggle levers being arranged in crossed relation between said second. pair of members, the upper and lower elements of said levers engaging with said second pair of members respectively below and above the medial plane of said members.

ROY D. KING. 

